doubt if that info is available, I was there camping a couple of years ago and there was no tourists there apart from those driving past. A villager might put you up but a trucker would sleep in the cab so there no incentive to start up one.

During trip in November had stopped at Chumathang for a tea. That time came across this guest house. Still some work was going on. They will be open in winter with hot water supply and local type of toilets.